Method for preparing crucible for smelting titanium and titanium alloys

Abstract

The invention relates to a method for preparing a crucible for smelting titanium and titanium alloys, which uses yttrium oxide and appropriate amount of additive as main raw materials to obtain the crucible by using a reasonable sintering schedule between 1,300 and 1,800 DEG C after forming by an isostatic pressing or a pouring process. The yttrium oxide-based crucible prepared by the method has good service performances like thermal shock stability and erosion resistance, can be used to smelt and cast of the titanium and the titanium alloys to prepare titanium and titanium alloy castings with good performance. The method is low in sintering temperature, energy-saving and environment-friendly, and improves the production efficiency. When used, the yttrium oxide crucible is provided with protective measures like an alumina crucible and a graphite crucible on the outside, or is added with oxidation inhibitor like titanium powder and magnesium powder to improve the service life and the smelting quality of the titanium and the titanium alloys. In addition, a damaged crucible can be repaired by casting method and the like so as to prolong the service life of the curcible.

Description

Technical field: [0001] The invention relates to ceramic material preparation technology, in particular to a preparation method of a crucible for melting titanium and titanium alloys. Background technique: [0002] Titanium and titanium alloys have a series of excellent properties such as low density, high specific strength, and good corrosion resistance. They are extremely important structural and functional materials. They have very important applications in the fields of aviation, aerospace, vehicle engineering, and biomedical engineering. value and broad application prospects. Among them, high-purity titanium, Ti-6Al-4V, Ti-6Al-2Sn-4Zr-6Mo, Ti-5Al-2.5Sn, Ti-6Al-2Sn-4Zr-2Mo, Ti-13V-11Cr-3Al, Ti-8Cr Several titanium and titanium alloys such as -5Mo-5V-3Al, Ti3Al(α) and TiAl(γ) are widely studied and used. [0003] Due to the high energy consumption and high price of titanium and titanium alloy products, although titanium is the fourth richest mineral resource after iron,...

AI Technical Summary

Problems solved by technology

However, due to the high chemical activity of titanium in the molten state, it is easy to chemically react with refractory materials during the casting process, which deteriorates the surface quality of the casting and reduces the mechanical properties, so the melting and casting of titanium and titanium alloys are difficult. , Improving the corrosion resistance of refractories plays a decisive role in the development of titanium industry

Although graphite, metal oxides (zirconia, calcium oxide, yttrium oxide, etc.), non-oxide materials (boron nitride, zirconium carbide, silicon carbide, zirconium boride, etc.), metals (molybdenum, carbon steel, copper, etc.) Refractories can basically meet the requirements, but there are two main defects: one is that a reaction layer is formed on the surface of the casting, which affects the surface quality of the casting; Reduced service life

However, the melting point of yttrium oxide is high, and it is difficult to prepare dense yttrium oxide ceramic materials. In addition, the thermal shock performance of yttrium oxide ceramics is poor, so the preparation of dense yttrium oxide crucibles with good thermal shock resistance is of great importance to the development of titanium and titanium alloy industries. very important